Capital Gains Tax: Registration Date Vs. Allotment date

Dear CAs,

I was allotted industrial land in 2010 from SIDCO. SIDCO's clause stated that I needed to construct a building and install some machinery. Only then will the land be registered to me. The place has been in our possession since 2010.

In 2013 we completed the construction and it costed 15 Lakh rupees.

In 2014 the land was registered to me by the area's sub-registrar's office.

In 2023, I sold the land with shed for 33 Lakh rupees.

My question is:

Can I add my construction cost as "Cost of improvement" when calculating the Capital Gains tax now? I ask this because I spent money on construction (in 2013) even before the plot was registered to me (2014).

Thank you.